This invention relates generally to display terminal devices and particularly display terminal devices including coupling mechanisms for permitting partial tilt and partial rotation of a display portion with respect to a base member.
It is desirable to mount the video display terminals associated with many types of office and computer systems so that the terminals can be easily adjusted for the viewer's comfort and for glare-free viewing. The display portion of the terminals are preferably movable through a range of positions by the viewer who sits before the terminal.
Such terminals typically incorporate a cathode ray tube (CRT) in the display portion and are fairly relatively heavy. Consequently the coupling mechanisms by which the display portions tilt and rotate must be constructed to give sturdy and secure support. Furthermore, the display portions should move easily through the range of positions, but not so easily that they are easily knocked away from their adjusted position. It is also usually desirable to be able to adjust the position of the display portion in one plane without fear of inadvertently changing its orientation in the other.
Various tilting, rotating and swivelling coupling mechanisms for mounting one piece of equipment on another that have been devised in the prior art are exemplified by U.S. Pat. Nos. 4,068,961, 1,166,752, and 1,956,614. The coupling mechanisms shown in these patents have many different features. However, none include satisfactory isolation of two independent degrees of rotational freedom. Moreover, none show satisfactory means for holding a position following adjustment. U.S. Pat. No. 3,970,792 discloses a terminal swivel tilt mechanism which permits independent degrees of rotational freedom, but requires two rockers (for tilt) which must be specifically located with respect to the display center of gravity to permit a tilt adjustment to be maintained.
It is an object of this invention to provide a new and improved tilting and rotating mechanism for coupling a display portion of a terminal to the base portion of the terminal in a way that provides secure and steady attachment and support, that allows the display portion to be adjustably and independently tilted or rotated. Another object is to provide an improved mechanism for maintaining an adjusted position of the display portion of a terminal.